1. Field
The present invention relates generally to communications systems, and more specifically, to a radio with duplexer bypass capability.
2. Background
Radio refers to a system of communications employing electromagnetic waves propagated through free space. Radio is commonly used as a public medium to send commercial broadcasts from a radio transmitter to anyone with a radio receiver. However, radio can also be used as a private medium. Cellular and cordless telephones are common examples of radio transceivers, which are devices that can both transmit and receive signals.
Many radio transceivers are designed for full duplex operation. Full duplex refers to the transmission of signals in two directions simultaneously. By way of example, cellular and cordless telephones are typically a full duplex device because both users can speak at once. In contrast, a walkie-talkie is a half duplex device because only one user can transmit at a time. Full duplex operation is generally supported with a duplexer connecting both the receiver and transmitter to a single antenna. The problem with this approach is that the duplexer introduces loss into the signal directed to the receiver. This loss tends to reduce the noise figure performance of the receiver, and as a result, limits the data rate of the signal that can be detected by the receiver. Accordingly, there is a need in the art for a methodology which allows full duplex operation without significantly degrading the noise figure of the receiver.